An evaluation of post-production facial composite enhancement techniques
The Journal of Forensic Practice
Article publication date: 9 November 2015
The purpose of this paper is to describe four experiments evaluating post-production enhancement techniques with facial composites mainly created using the EFIT-V holistic system.
Experiments 1-4 were conducted in two stages. In Stage 1, constructors created between one and four individual composites of unfamiliar targets. These were merged to create morphs. Additionally in Experiment 3, composites were vertically stretched. In Stage 2, participants familiar with the targets named or provided target-similarity ratings to the images.
In Experiments 1-3, correct naming rates were significantly higher to between-witness 4-morphs, within-witness 4-morphs and vertically stretched composites than to individual composites. In Experiment 4, there was a positive relationship between composite-target similarity ratings and between-witness morph-size (2-, 4-, 8-, 16-morphs).
The likelihood of a facial composite being recognised can be improved by morphing and vertical stretch.
This paper improves knowledge of the theoretical underpinnings of these facial composite post-production enhancement techniques. This should encourage acceptance by the criminal justice system, and lead to better detection outcomes.
The authors would like to thank Josi Cakebread, Amy Skelton, Sarah Thorniley, Helen Little, Sarah Poland, Natalie Baker, Sheena Belfon, and Lala Jammeh for their assistance in collecting data for this project. The research was partly funded by two internal University of Greenwich grants to the first author. Part of this research was presented at the American Psychology-Law Society Annual Meeting, 4th International Congress of Psychology and Law, Miami, Florida, USA, March 2011. Chris Solomon and Stuart Gibson are faculty members of the University of Kent and directors of VisionMetric Ltd. VisionMetric Ltd markets the EFITV and E-FIT facial composite systems. Solomon and Gibson’s contribution to this work was to facilitate the data collection that took place at the University of Kent, development of the software and provision of software support. Data collection, analyses and interpretation were performed by Davis, Simmons, and Sulley.
Davis, J.P., Simmons, S., Sulley, L., Solomon, C. and Gibson, S. (2015), "An evaluation of post-production facial composite enhancement techniques", The Journal of Forensic Practice, Vol. 17 No. 4, pp. 307-318. https://doi.org/10.1108/JFP-08-2015-0042
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